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GCSE level questions on light

Q5.

(a) Complete the ray diagram below to show the reflection of light from the surface box of a plane mirror.

You should:

draw the normal line

- normal drawn at 90° at the point where the incident ray strikes the mirror

draw the reflected ray.

- straight line drawn with a ruler on opposite side of normal

- angle of incidence = angle of reflection

- arrow head in correct direction (away from mirror)

[4 marks]

(b) Willow and Buffy investigated the reflection of light by a plane mirror. The diagram below shows the different equipment they used.

Explain two ways that Willow's method is better than Buffy's.

The protractor drawn on the paper means you do not have to mark the rays position on the paper and move the mirror, and position the protractor for each ray, in order to measure the angles - so you are more likely to record the correct angle of incidence and/or reflection.

The laser ray does not diverge as it is a very narrow band of wavelengths making it easier to judge the centre (position) of the ray.

[4 marks]

(Total 8 marks)